A range of factors may be behind the cylinder problems. File Image / Pixabay
Lloyd's Register's Fuel Oil Bunker Analysis Service (FOBAS) has reported a surge in engine cylinder liner wear incidents since the shipping industry's shift to using very low sulfur fuel oil (VLSFO).
FOBAS data shows cylinder component damage incidents in large two-stroke engines roughly doubled in the eight months to June 2020 compared with the same period a year earlier, the company said in a note to clients Monday.
But the trend has started to dissipate since March 2020, FOBAS said.
The company has investigated whether the use of new VLSFO blends may be responsible for the increase, with uncertain results.
"It is not straightforward to link the fuel quality with the reported issues," FOBAS said.
Many of the vessels reporting incidents were not fitted with hard-coated piston rings as recommended in OEM guidelines, which may have left them more vulnerable.
The use of lubricants of 70BN or higher, rather than the 40BN ones used by most of the global fleet, may also help protect engines, according to the research.
"In cases such as damage to cylinder liner and piston rings, it is important to seek guidance from the engine manufacturers," the company said.
"Moreover, ship operators should refer to their engine operations manual, consult latest service letters and also apply a best practice approach to mitigate and avoid future occurrences."